This invention relates to compositions which are used to prepare cell samples for cytological examination, especially where the samples are urine or bladder wash samples or fine needle aspirations of prostate or kidney tissues or organs.
Cytologic analyses are often carried out in central laboratories. Preparation and preservation of the cells and minimization of artifacts is a crucial consideration in shipping samples to central laboratories. With urine samples, among the more common interfering artifacts are crystals that form from the oxalates and phosphates within the urine. Although other substances in the urine can also form crystals, by far the most common are phosphates and oxalates. The crystals can sometimes be so dense as to obscure the cells, interfere with proper staining of the cells, interfere with adherence of the cells to microscope slides, or complicate the analysis of the cells.
In spite of the problems caused by crystal formation within urine and bladder wash samples, there are no cell fixative or preservative compositions for fixing urine which are effective in inhibiting the formation of crystals.
A cell preparative composition which preserved the cells with the retention of the characteristic cell morphology and which simultaneously inhibited crystal formation in the sample or dissolved crystals already within the sample and which also promoted adherence of cells to examination slides would be of great value in the field of cytological analyses.